Respiratory mask

ABSTRACT

A respiratory mask assembly for use with a patient, and that is suited for use with children ranging in age from about 2-7 years, includes a flexible patient interface structure arranged to interface with and deliver air to the patient&#39;s nose, the patient interface structure including cylindrical protrusions extending from respective opposite sides of the patient interface structure adjacent the patient&#39;s nares; a frame configured to support the patient interface structure, the frame including a pair of cylinders, each cylinder configured to receive a respective cylindrical protrusion of the patient interface structure; headgear arranged for releasable attachment to the frame; an air delivery tube connected to either one of the cylindrical protrusions; and a plug connected to the other one of the cylindrical protrusions.

CROSS REFERENCE TO RELATED APPLICATIONS

This application is a continuation of U.S. application Ser. No.13/097,501, now allowed, filed Apr. 29, 2011, which application claimsthe benefit of U.S. Applications 61/330,039 and 61/418,037, filed Apr.30, 2010 and Nov. 30, 2010, respectively, the entire contents of eachbeing incorporated herein by reference.

BACKGROUND OF THE TECHNOLOGY

Patient interfaces, such as a nasal mask assembly, for use withContinuous Positive Airway Pressure Devices (CPAP), flow generators orblowers in the treatment of sleep disordered breathing (SDB), such asObstructive Sleep Apnea (OSA), typically include a soft-patientcontacting portion, such as a cushion, and a rigid shell or frame. Inuse, the patient interface is held in a sealing position by headgear soas to enable a supply of air at positive pressure to be delivered to thepatient's airways.

Factors in the efficacy of therapy and compliance of patients withtherapy include: mask comfort; sealing; stability (e.g. aids insealing); fit; and ease of use.

Another factor of the prior art is manufacturability.

While there are a large number of patient interfaces designed foradults, there are relatively few designed to suit infants and children.Prior art masks for treating children are deficient in several areas.For example, infants may lie on their stomachs when they sleep. Theconfiguration of prior art masks are too large and/or bulky on theinfant's face or forehead to readily allow for this. Other mask designsare too flexible and might collapse (e.g. Sullivan et al.—WO 01/32250A1).

It is desirable for parents to have a clear view of their child when thechild is wearing a mask. Some prior art masks do not allow for this(e.g. mask covers too much of child's face). It is also desirable forclinicians and caregivers to have a clear view of the nares to ensurethat they are not obstructed.

Some prior art masks include hard/rigid components. This may causepressure sores and can be perceived negatively bypatients/clinicians/parents.

Prior art masks designed for adults are also generally not designed tobe fitted by a third party (e.g. clips are difficult to operate), suchas would be useful in a mask for a child or infant.

SUMMARY OF THE TECHNOLOGY

An aspect of the present technology relates to a respiratory maskassembly designed to suit infants and children.

Another aspect of the present technology relates to a respiratory maskassembly in which an air delivery tube is connectable to either a rightside or a left side of the mask assembly.

Another aspect of the present technology relates to a respiratory maskassembly in which an air delivery tube is connectable to either a rightside or a left side of the mask assembly, and a plug is connectable tothe other side of the mask assembly opposite from the air delivery tube.

Another aspect of the present technology relates to a respiratory maskassembly that includes a patient interface (e.g., flexible) and a frame(e.g., rigid) adapted to receive and support the patient interface,where at least one of the patient interface and the frame includes atleast one orientation element adapted to indicate a correct orientationbetween a patient interface and the frame.

Another aspect of the present technology relates to a respiratory maskassembly that includes a patient interface structure (e.g., flexible)arranged to interface with and deliver air to a patient, the patientinterface having one or more protrusions (e.g., cylindrical), extendingfrom respective opposite sides of the patient interface structureadjacent the patient's nares, and a frame configured to support thepatient interface structure, the frame including one or more receivingmembers, e.g., cylinders, each receiving member configured to receive arespective protrusion of the patient interface structure.

Another aspect of the present technology relates to a respiratory maskassembly that includes a patient interface, (e.g., flexible) arranged tointerface with a deliver air to patient, and a frame configured tosupport the patient interface, where the patient interface is generallytrapezoidally shaped with one or more protrusions (e.g., cylindrical)extending from each side of the patient interface.

Another aspect of the present technology relates to a respiratory maskassembly that includes a patient interface (e.g., flexible) arranged tointerface with an deliver air to a patient, the patient interface havingone or more protrusions (e.g., cylindrical) extending from respectiveopposite sides of the patient interface adjacent the patient's nares,and a frame configured to support the patient interface, where each ofthe protrusions comprises an inner protrusion and an outer protrusion(e.g., cylindrical).

Another aspect of the present technology relates to a respiratory maskassembly that includes a patient interface (e.g., flexible) arranged tointerface with and deliver air to a patient, the patient interfacehaving one or more protrusions (e.g., cylindrical) extending fromrespective opposite sides of the patient interface adjacent thepatient's nares, a frame configured to support the patient interface andan air delivery tube connected to either one of the protrusions, whereat least one said protrusion decouples movement of the air delivery tubefrom the patient interface and/or from the frame.

Another aspect of the present technology relates to a respiratory maskassembly that includes a patient interface structure arranged tointerface with and deliver air to a patient, the patient interfacehaving one or more protrusions extending from respective opposite sidesof the patient interface structure adjacent the patient's nares, a frameconfigured to support the patient interface structure, a plug adapted tobe sealingly connectable to one of the protrusions, and a post extendingfrom the frame adapted to receive and retain the plug when the plug isremoved from the respective protrusion.

Another aspect of the present technology relates to a respiratory maskassembly for use with a patient and that is particularly suited for usewith children, e.g. for treatment of SDB, such as obstructive sleepapnea (OSA), or congenital abnormalities. The respiratory mask assemblymay include a cushion arranged to interface with and deliver air to thepatient's nose. The cushion may have a tube connection portion at one orboth sides adjacent the patient's nares, the tube connection portionbeing arranged to connect to an air delivery tube. This location alsoreduces destabilising moments produced by tube drag forces. A more rigidsupport structure adjacent the cushion may be provided to stabilize thecushion and prevent it from collapsing. Headgear may also be providedand arranged for releasable attachment to the support structure.

Another aspect of the present technology provides a respiratory mask foruse with a patient including a cushion arranged to interface with anddeliver air to the patient's nose, a support structure adjacent thecushion, and headgear arranged for releasable attachment to the supportstructure. The support structure extends over the patient's nasal bridgebut not over the apex of the patient's nose, such that the supportstructure substantially stops the cushion from collapsing when a forceis applied to a front side of the mask. This allows a patient to sleepon their face and still receive effective respiratory treatment.

Another aspect of the present technology is that the cushion may betranslucent to the extent that the patient's nares can be inspectedthrough the cushion, or the cushion may be substantially transparent(e.g., water clear).

Another aspect of the present technology is that the cushion can sealacross the nose bridge at any point along its length (i.e. from the topof the nose bridge to the nose tip) so that the cushion can seal on avariety of different size noses. This is desirable as the size of achild's nose can differ depending on their age.

Another aspect of the present technology relates to a patient interfacesystem for delivering breathable gas to a patient comprising a patientinterface structure arranged to interface with and deliver air to thepatient's nose, the patient interface structure comprising one or moreprotrusions extending from respective opposite sides of the patientinterface structure adjacent the patient's nares; a frame configured tosupport the patient interface structure, the frame comprising one ormore protrusion, each protrusion having an inner surface configured toreceive a respective protrusion of the patient interface structure;headgear arranged for releasable attachment to the frame; and an airdelivery tube connected to either one of the protrusions.

Another aspect of the present technology relates to a patient interfacesystem for delivering breathable gas to a patient comprising a patientinterface structure arranged to interface with and deliver air to a noseof the patient in use, the patient interface structure having agenerally polygonal shape, e.g., trapezoidal shape, with one or moreprotrusions extending from respective opposite sides of the patientinterface structure, a frame configured to support the patient interfacestructure, the frame comprising one or more receiving members, (e.g.,cylinders) each configured to receive a respective cylindricalprotrusion of the patient interface structure, headgear arranged forreleasable attachment to the frame, and an air delivery tube connectedto either one of the cylindrical protrusions.

Another aspect of the present technology relates to a patient interfacesystem for delivering breathable gas to a patient comprising a flexiblepatient interface structure arranged to interface with and deliver airto a nose of the patient in use, the patient interface structure havingone or more protrusions extending from respective opposite sides of thepatient interface structure, each said cylindrical protrusion having aninner protrusion and an outer protrusion, and the patient interfacestructure having a thickened portion with an exhalation vent, a frameconfigured to support he patient interface structure, the frameconfigured to receive the one or more protrusions of the patientinterface structure, the frame including an aperture adapted to receivethe thickened portion of the flexible patient interface structure,headgear arranged for releasable attachment to the frame, and an airdelivery tube connected to at least one of the cylindrical protrusions,wherein the thickened portion of the flexible patient interfacestructure is shaped to conform to the shape of the aperture of the frameso that the flexible patient interface structure is correctly assembledto the frame, e.g., when the aperture of the frame receives thethickened portion of the flexible patient interface structure.

According to another aspect of the present technology a plug or cap maybe provided to one or more protrusions. The plug may be tethered to theframe or patient interface structure. The tether may be separately orintegrally formed with the respiratory mask assembly. Alternatively, oradditionally, a valve may be provided to one or several cylindricalprotrusions. The valve may be integrally formed with the patientinterface structure. The valve may be provided in the cap or plug. Theplug may be connected to the patient interface structure, for example bya living hinge. Alternatively, the plug or cap with the valve may bepermanently, or removably, snapped into the frame.

According to another aspect of the present technology, an exhalationvent may be provided to the patient interface. The exhalation vent maycomprise at least one aperture, or at least one array of apertures. Theexhalation vent may be disposed on a thickened portion of the patientinterface. The exhalation vent may be disposed on an elbow, frame orplug portion of the mask system,

According to another aspect of the present technology, one or moreprotrusion and/or a plug may include at least one element adapted toretain the plug in the respective protrusion.

According to another aspect of the present technology, one ore moreprotrusions and/or an elbow may include at least one element adapted toretain the elbow in the respective cylindrical protrusion.

According to another aspect of the present technology, a headgear isprovided that may be adjustable from the front or towards the face ofthe patient to enable easier adjustment of the headgear when it is beingworn by a child.

According to another aspect of the present technology is a quick releasebuckle to allow a caregiver to fit the headgear as well as remove theheadgear quickly in an emergency.

Other aspects, features, and advantages of this invention will becomeapparent from the following detailed description when taken inconjunction with the accompanying drawings, which are a part of thisdisclosure and which illustrate, by way of example, principles of thistechnology.

BRIEF DESCRIPTION OF THE DRAWINGS

The accompanying drawings facilitate an understanding of the variousembodiments of the technology. In such drawings:

FIG. 1 schematically depicts a front perspective view of a respiratorymask assembly according to a first embodiment of the technology;

FIGS. 2A-2C schematically depict a support structure, or frame, of therespiratory mask assembly of FIG. 1 ;

FIG. 3 schematically depicts a front perspective view of a patientinterface, or cushion, of the respiratory mask assembly of FIG. 1 ;

FIG. 4 schematically depicts a rear perspective view of the patientinterface, or cushion, of FIG. 3 ;

FIG. 5 schematically depicts a rear perspective view of the patientinterface, or cushion, of FIG. 3 ;

FIG. 6 schematically depicts a cross-sectional section view of thepatient interface, or cushion, of FIGS. 3-5 ;

FIG. 7 schematically depicts an enlarged cross-sectional view of aportion of the patient interface, or cushion, of FIG. 6 ;

FIG. 8 schematically depicts a cross-sectional view of a connection ofthe support structure, or frame, and the patient interface, or cushion,of the respiratory mask assembly of FIG. 1 ;

FIG. 9 schematically depicts a cross-sectional view of a connection of aplug, and the patient interface, or cushion, of the respiratory maskassembly of FIG. 1 ;

FIG. 10 schematically depicts a side view of a patient interface, orcushion, according to another embodiment of the technology;

FIG. 11 schematically depicts a side view of an elbow and tube of therespiratory mask assembly of FIG. 1 ;

FIGS. 12 and 13 schematically depict the elbow of FIG. 11 ;

FIG. 14 schematically depicts a cross-sectional view of the elbow ofFIGS. 11-13 ;

FIG. 15 schematically depicts a cross-sectional view of a connectionbetween the elbow of FIGS. 11-14 and the patient interface, or cushion,of FIGS. 3-7 ;

FIGS. 16-18 schematically depict a quick release buckle according to anembodiment of the technology;

FIG. 19 schematically depict a connection of straps of a patientinterface positioning and support structure, or headgear, by the quickrelease buckle of FIGS. 16-18 ;

FIGS. 20 and 21 schematically depict front views of a respiratory maskassembly according to embodiments of the technology;

FIG. 22 schematically depicts a front view of a cushion, or patientinterface structure, according to an embodiment of the technology;

FIG. 23 schematically depicts a cross-sectional view of the cushion ofFIG. 22 along line 23-23;

FIG. 24 schematically depicts a detailed cross-sectional view of sideportions of the base wall and membrane of the section of FIG. 23 ;

FIG. 25 schematically depicts a cross-sectional view of the cushion ofFIG. 22 along line 25-25;

FIG. 26 schematically depicts a detailed cross-sectional view of sideportions of the base wall and membrane of the section of FIG. 25 ;

FIG. 27 schematically depicts a cross-sectional view of the cushion ofFIG. 22 along line 27-27;

FIG. 28 schematically depicts a detailed cross-sectional view of the topportion of the base wall and membrane of the section of FIG. 27 ;

FIG. 29 schematically depicts a detailed cross-sectional view of thebottom portion of the base wall and membrane of the section of FIG. 27 ;

FIG. 30 schematically depicts a rear view of the cushion of FIG. 22 ;

FIG. 31 schematically depicts a cross-sectional view of the cushion ofFIG. 22 along line 31-31;

FIG. 32 schematically depicts a cross-sectional view of the cushion ofFIG. 22 along line 32-32;

FIG. 33 schematically depicts a cross-sectional view of the cushion ofFIG. 22 along line 33-33;

FIG. 34 schematically depicts a cross-sectional view of the cushion ofFIG. 22 along line 34-34;

FIG. 35 schematically depicts a cross-sectional view of the cushion ofFIG. 22 along line 35-35;

FIG. 36 schematically depicts a cross-sectional view of the cushion ofFIG. 22 along line 36-36;

FIG. 37 schematically depicts a rear perspective view of a respiratorymask assembly with closed valve flaps according to another embodiment ofthe technology;

FIG. 38 schematically depicts a rear perspective view of the respiratorymask assembly of FIG. 37 with open valve flaps;

FIG. 39 schematically depicts a side view of the respiratory maskassembly of FIG. 37 with closed valve flaps;

FIG. 40 schematically depicts a rear perspective view of the cushion ofthe respiratory mask assembly of FIG. 37 with closed valve flaps;

FIG. 41 schematically depicts a cross-sectional view of a cushion and anelbow according to another sample embodiment of the technology;

FIG. 42 schematically depicts a cross-sectional view of the cushion ofFIG. 41 with the elbow attached;

FIG. 43 schematically depicts a cross-sectional view of a cushion and anelbow according to another sample embodiment of the technology;

FIG. 44 schematically depicts a cross-sectional view of the cushion ofFIG. 43 with the elbow attached;

FIG. 45 schematically depicts a cross-sectional view of a cushion, a capincluding a valve and an elbow according to another sample embodiment ofthe technology;

FIG. 46 schematically depicts a cross-sectional view of the cushion andthe cap of FIG. 45 with the elbow attached to the cap;

FIG. 47 schematically depicts a perspective view of the cap of FIG. 45 ;

FIG. 48 schematically depicts a front view of a frame, or supportstructure, and a tether according to a sample embodiment of thetechnology;

FIGS. 49 and 50 schematically depict a plug adapted to connect to thetether of FIG. 48 ;

FIG. 51 schematically depicts a tether according to another sampleembodiment of the technology;

FIG. 52 schematically depicts a connection arrangement for a tether tothe frame of the respiratory mask assembly according to a sampleembodiment of the technology;

FIG. 53 schematically depicts a connection arrangement for a tetheraccording to another sample embodiment of the technology;

FIG. 54 schematically depicts a connection arrangement for a tetheraccording to still another sample embodiment of the technology;

FIGS. 55 and 56 schematically depict perspective views of a port for usewith a respirator mask assembly according to a sample embodiment of thetechnology;

FIG. 57 schematically depicts a perspective view of a port with anextension member and barb according to another sample embodiment of thetechnology;

FIG. 58 schematically depicts a partial rear view of connection of thebarb of FIG. 57 to a wing portion of a frame;

FIG. 59 schematically depicts a perspective view of a port with anextension member according to another sample embodiment of thetechnology;

FIG. 60 schematically depicts a cross-sectional view of the port of FIG.59 in a frame with the extension member connected to the wing portion ofthe frame;

FIG. 61 schematically depicts a port with an extension member accordingto another sample embodiment of the technology;

FIG. 62 schematically depicts a cross-sectional view of the port of FIG.61 in a frame with the extension member connected to the wing portion ofthe frame and to a reinforcing structure of the headgear;

FIG. 63 schematically depicts a perspective view of a port with anextension member according to another sample embodiment of thetechnology;

FIG. 64 schematically depicts a cross-sectional view of the port of FIG.63 in a frame with the extension member connected to the wing portion ofthe frame;

FIG. 65 schematically depicts a perspective view of a port with a tetheraccording to another sample embodiment of the technology;

FIG. 66 schematically depicts a perspective view of a port with a snaparm according to another sample embodiment of the technology;

FIG. 67 schematically depicts a perspective view of a port with two snaparms according to another sample embodiment of the technology;

FIG. 68 schematically depicts a perspective view of the port of FIG. 67and connection to a frame according to another sample embodiment of thetechnology;

FIG. 69 schematically depicts a tether with retention lugs according toanother sample embodiment of the technology;

FIG. 70 schematically depicts a tether with retention lugs and a ribaccording to another sample embodiment of the technology;

FIG. 71 schematically depicts a tether with retention lugs and a handleaccording to another sample embodiment of the technology;

FIG. 72A schematically depicts a tether connecting a plug to a frameaccording to another sample embodiment of the technology;

FIG. 72B schematically depicts a tether connecting a plug to a frameaccording to another sample embodiment of the technology;

FIGS. 72C-72I depict a patient interface system (e.g. respiratory maskassembly) according to another sample embodiment of the technology;

FIGS. 73 and 74 are cross-sectional views illustrating retention lugsthat connect the tether to the frame according to other sampleembodiments of the technology;

FIG. 75 schematically depicts a partial bottom view of the retentionlugs of the frame according to another sample embodiment of thetechnology;

FIG. 76 schematically depicts a side view of the retention lugs of thetether;

FIG. 77 is a cross-sectional view illustrating the retention lugsconnected to the frame according to another sample embodiment of thetechnology;

FIG. 78 schematically depicts a front view of a cushion and frameaccording to another sample embodiment of the technology;

FIG. 79 schematically depicts a rear view of a cushion according toanother sample embodiment of the technology;

FIG. 80 is a cross-sectional view of a cushion on a model patient's headaccording to another sample embodiment of the technology;

FIG. 81 schematically depicts a cushion and frame on a model patient'shead;

FIG. 82 schematically depicts a partial rear view of a cushion;

FIG. 83 schematically depicts a cross-sectional view of the cushion ofFIG. 82 along line 83-83;

FIG. 84 schematically depicts a cross-sectional view of the cushion ofFIG. 82 along line 84-84;

FIG. 85 schematically depicts a cross-sectional view of the cushion ofFIG. 82 along line 85-85;

FIG. 86 schematically depicts a cross-sectional view of the cushion ofFIG. 82 along line 86-86;

FIG. 87 schematically depicts a cross-sectional view of the cushion ofFIG. 82 along line 87-87;

FIG. 88 schematically depicts a cross-sectional view of the cushion ofFIG. 82 along line 88-88;

FIG. 89 schematically depicts a cross-sectional view of the cushion ofFIG. 82 along line 89-89;

FIG. 90 schematically depicts a cross-sectional view of the cushion ofFIG. 82 along line 90-90;

FIG. 91 schematically depicts a cross-sectional view of the cushion ofFIG. 82 along line 91-91;

FIG. 92 schematically depicts a perspective view of a plug connected toa tether according to another sample embodiment of the technology;

FIG. 93 schematically depicts the tether of FIG. 92 ;

FIG. 94 schematically depicts a perspective view of connection of a plugto a frame of a mask assembly according to another sample embodiment ofthe technology;

FIG. 95 schematically depicts a front view of a frame and cushion of amask assembly according to another sample embodiment of the technology;

FIG. 96 schematically depicts a partial side view of a mask assemblyillustrating connection of a tether between a frame and a plug accordingto another sample embodiment of the technology;

FIG. 97 schematically depicts a front view of a mask assemblyillustrating an aperture for connection of a tether between a frame anda plug according to another sample embodiment of the technology;

FIG. 98 schematically depicts a perspective view illustrating connectionof a tether to a plug according to another sample embodiment of thetechnology;

FIG. 99 schematically depicts a partial perspective view of a maskassembly illustrating connection of the tether and plug of FIG. 98 to aframe;

FIG. 100 schematically depicts a front view of a mask assemblyillustrating an aperture for connection of a tether between a frame anda plug according to another sample embodiment of the technology;

FIG. 101 schematically depicts a perspective view illustratingconnection of a tether to a plug according to another sample embodimentof the technology;

FIG. 102 schematically depicts a perspective view of a mask assemblyillustrating connection of the tether and plug of FIG. 101 to a frame;

FIG. 103 schematically depicts a front view a front view of a maskassembly illustrating an aperture for connection of a tether between aframe and a plug according to another sample embodiment of thetechnology;

FIG. 104 schematically depicts a perspective view of a plug having aconnector according to another sample embodiment of the technology;

FIG. 105 schematically depicts a mask assembly having the plug and theconnector of FIG. 104 connected to a frame;

FIG. 106 schematically depicts a perspective view of a mask assemblyhaving a post and a connector according to another sample embodiment ofthe technology;

FIG. 107 schematically depicts a perspective view of a mask assemblyhaving a post and a connector according to another sample embodiment ofthe technology;

FIG. 108 schematically depicts a perspective view of the mask assemblyof FIG. 107 with the plug retained onto the post according to anothersample embodiment of the technology;

FIG. 109 schematically depicts a perspective view of a mask assemblyhaving a post and a connector according to another sample embodiment ofthe technology;

FIG. 110 schematically depicts a perspective view of the mask assemblyof FIG. 109 with the plug retained onto the post according to anothersample embodiment of the technology;

FIGS. 111 and 112 schematically depict a respiratory mask assemblyaccording to another sample embodiment of the technology;

FIG. 113 schematically depicts a pressure port, a pressure tube, and anadaptor for the pressure port according to a sample embodiment of theinvention;

FIG. 114 schematically depicts a respiratory mask assembly including apressure port and a tether according to another sample embodiment of thetechnology;

FIGS. 115 and 116 schematically depict a headgear including a tether fora pressure port, for example;

FIGS. 117 and 118 schematically depict a tether and a pressure portaccording to another sample embodiment of the technology;

FIG. 119 schematically depicts a pressure port, a tether and a pressuretube according to another sample embodiment of the technology;

FIGS. 120-122 schematically depict a pressure port according to anothersample embodiment of the technology; and

FIGS. 123-127 depict a patient interface structure (e.g. cushion) andpatient interface system (e.g. respiratory mask assembly) according toanother sample embodiment of the technology.

DETAILED DESCRIPTION

The following description is provided in relation to several embodimentswhich may share common characteristics and features. It is to beunderstood that one or more features of any one embodiment may becombinable with one or more features of the other embodiments. Inaddition, any single feature or combination of features in any of theembodiments may constitute additional embodiments.

In this specification, the word “comprising” is to be understood in its“open” sense, that is, in the sense of “including”, and thus not limitedto its “closed” sense, that is the sense of “consisting only of”. Acorresponding meaning is to be attributed to the corresponding words“comprise”, “comprised” and “comprises” where they appear.

The term “air” will be taken to include breathable gases, for exampleair with supplemental oxygen. It is also acknowledged that the blowersdescribed herein may be designed to pump fluids other than air.

It should be noted that the terms “mask” and “mask assembly” and theterm “patient interface system” are used interchangeably in thisspecification. It should also be appreciated that the terms “cushion”and “patient interface structure” are used interchangeably in thisspecification. It should further be appreciated that the terms“headgear” and “patient interface positioning and support system” areused interchangeably in this specification.

An air delivery tube, for interconnection between a Continuous PositiveAirway Pressure Device and a Patient Interface, may have an internaldiameter of between 4 mm and 15 mm Preferably, the air delivery tube mayhave an internal diameter of between 4 mm and 10 mm Preferably, the airdelivery tube may have an internal diameter of between 4 mm and 8 mm Onebenefit of this sample embodiment is that it reduces the weight and/orbulk of the tube and the friction that results from movement of the tubeacross a surface and therefore reduces the pull (i.e., “tube drag”) onthe patient interface.

The present technology relates to a respiratory system that has beendesigned for pediatric use (i.e. with infants or children) althoughaspects of the system may be used advantageously by adults. Therespiratory system comprises a mask and a blower (e.g. a flow generator,a Continuous Positive Airway Pressure (CPAP), or a Variable PositiveAirway Pressure Device (VPAP) device) and an air delivery tubingarrangement connecting the two.

1. Respiratory Mask Assembly

Referring to FIG. 1 , a respiratory mask assembly 10 comprises a supportstructure, or frame, 14 which supports a patient interface structure, orcushion, 12 configured to sealingly engage the face of the patient. Atube, or hose, or conduit 2 is connected to the cushion 12 by an elbow18 for delivering a flow of breathable gas to the patient. A patientinterface positioning and support system, or headgear, 16 is configuredto position and support the cushion 12 in sealing engagement with theface of the patient.

The tube 2 is connected to the cushion 12 at a side portion of thecushion by the elbow 18. The opposite side portion of the cushion 12 isprovided with a plug, or cap 20 that seals the opening in the left sideof the cushion 12 or provides a port to receive an oxygen tube forexample. It should be appreciated that the configuration shown in FIG. 1may be changed so that the tubes 2 is connected to the side portion ofthe cushion 12 by the elbow 18 and the opposite side portion of thecushion 12 may be sealed by the plug 20. The plug 20 may have a handle21 that is adapted to be gripped by a user, to be pulled out of orpressed into the cushion 12.

1.1 Headgear

The headgear 16 may comprise side straps 4 that are configured to extendalong the sides of the face of the patient in use. The side straps 4 maybe configured to extend or be positioned between the patient's eyes andears in use. The ends of the side straps 4 are connected by a rear, orback, or middle strap 6 and top straps 8. The top straps 8 may beconfigured to extend from a first lateral side to a second lateral sideof the patient's head, and extend over the top of the patient's head toengage a crown of the patient's head in use. The rear straps 6 may beconfigured to extend around a back of the patient's head in use. A lowerrear strap 136 may be connected to the side straps 4. The lower rearstrap 136 may be configured to extend around a back of the neck of thepatient in use.

The rear straps 6 and the top straps 8 may each be adjusted by a buckle24. A buckle suitable for use to adjust the lengths of the rear straps 6and the top straps 8 is disclosed, for example, in U.S. PatentApplication Publication 2009/0044808 A1, the entire contents of whichare hereby incorporated by reference.

The side straps 4 of the headgear 16 may be provided with rigidizers,yokes, or reinforcing and/or stiffening structures 22, which areconfigured to reinforce and/or provide a degree of rigidity to the sidestraps 4. The reinforcing structures 22 may include a forward finger orextension 130, each connected to a wing portion 118 of the frame 14, anupper finger or extension 132, and a lower finger or extension 134. Thelower fingers 134 of the reinforcing structures 22 may be connected bythe lower rear strap 136 of the headgear 16. The reinforcing structures22 may be formed of, for example, nylon, polypropylene, polyurethane orother flexible material and have a thickness of, for example, about 0.9mm to 1.1 mm, for example about 1.0 mm. The forward fingers 130 may havea thickness of, for example, about 1.4 mm to 1.6 mm, for example about1.5 mm.

The straps 4, 6, 8, 136 may be formed of soft, flexible material, forexample a fabric laminate. The straps 4, 6, 8, 136 may have a pluralityof layers, for example a composite of a plurality of layers of differentmaterials. The ends of the straps 4, 6, 8, 136 may include hook materialthat allows the ends of the straps to be fastened to a loop material ona surface of the strap.

The reinforcing structures 22 may be attached to the straps 4 by, forexample, stitching 176, as shown in FIG. 1 . The stitching 176 may notextend the entire length of the reinforcing structures 22 so that endsof the reinforcing structures 22 may diverge from the straps. Thereinforcing structures 22 may also be attached to the straps by, forexample, adhesive, or placed in a pocket formed in the straps. Thereinforcing structures may also be provided as part of a compositelaminate with the reinforcing structure placed between two layers ofsoft, flexible strap material.

The ends of the straps may have hooks to engage the loop material of thestrap material. The hooks may be provided at the end of the straps ofthe headgear to prevent patients under the age of, for example, fouryears old from peeling the attached ends of the strap away and looseningthe straps and/or headgear.

Referring to FIG. 1 , the headgear is configured such that the buckles24 are positioned away from the sensitive area of the patient's face.The sensitive area of the patient's face is the area generally includingthe mouth, the nose, and the eyes. The buckles 24 may be adjusted for ayoung patient by a caregiver, parent or clinician by adjusting the endsof the rear straps 6 and the top straps 8 in a direction away from thesensitive area of the patient's face. According to one method of fittingthe respiratory mask assembly 10 on the patient, the top straps 8 andthe rear straps 6 are adjusted through the buckles 24 to an increasedlength. Then an end of the lower rear strap 136 is released fromconnection with the headgear, e.g. released from connection with areinforcing structure 22. The mask assembly is then placed over thepatient's head until the top straps 8 and the rear straps 6 engage thepatient's head and the cushion generally covers/engages the patient'snose. The end of the lower rear strap 136 is then reconnected to, forexample, the reinforcing structure 22. The lower rear strap 136, therear straps 6, and the upper straps 8 are then adjusted to provide acomfortable fit with the cushion 12 in sealing engagement with thepatient's face. The configuration of the respiratory mask assemblyallows a caregiver, clinician or parent to don the mask and the headgearon the child while facing the child, in that the headgear adjustmentpoints are conveniently arranged and adjustable as the parent orclinician is face-to-face with the child patient.

1.1.1 Quick Release Buckle

Referring to FIGS. 16-19 , a quick release buckle 80 may provide a quickand easy way to attach or remove the respiratory mask assembly 10. Asshown in FIGS. 17 and 18 , the quick release buckle 80 may comprise aslot 82 configured to accept a strap of the headgear, for example, asshown in FIG. 19 . The other end of the quick release buckle 80 mayinclude a hook 84 that is connected to the quick release buckle 80 bysection 86. A tab 94 is provided for the user or another such as acaregiver, a parent, a clinician, etc., to grasp the quick releasebuckle 80 to attach or remove the respiratory mask assembly 10 from thepatient.

As shown in FIG. 19 , the quick release buckle 80 may connect, forexample, the lower rear strap 136 to the lower finger 134 of thereinforcing structure 22. The lower rear strap 136 may be receivedthrough the slot 82 of the quick release buckle 80. As shown in FIG. 18, a pulling force 44 applied to the tab 94, for example by the caregiveror clinician, will permit the hook 84 of the quick release buckle 80 tobe separated from the reinforcing structure 22. The tab 94 is connectedto the reinforcing structure 22 via hook 84. Tab 94 may be adapted so asto be engageable by the fingers of the caregiver, patient or clinician,but not to interfere with the face of the patient. Tab 94 may have agripping region that may for example include ribs or bumps to make iteasier to grab the tab.

The quick release buckle 80 may also be adapted to function as anemergency latch, where the user or another such as a caregiver, aparent, a clinician, etc., may pull on the lower rear strap 136 to causethe hook 84 of the quick release buckle 80 to be separated from thereinforcing structure 22. Tension 42 on the lower rear strap 136 willcause the hook 84 of the quick release buckle 80 to flex or bend asshown by arrow 46 sufficiently to release the hook 84 from thereinforcing structure 22.

1.2 Support Structure/Frame

Referring to FIGS. 2A-2C, the support structure, or frame, 14 of therespiratory mask assembly 10 may be formed of a resilient material. Theframe 14 comprises cylinders 112 which receive cylindrical portions ofthe cushion 12 as will be described in more detail below. The cylinders112 are connected by abridge 120 which is configured to extend acrossthe nose of the patient in use. The wing portions 118 of the frame 14comprise connectors 138 that are configured to connect the frame 14 tothe headgear 16. Suitable connectors 138 for the frame 14 are disclosedin, for example, International Application PCT/AU2008/001557 (WO2009/052560 A1), the entire contents of which are incorporated herein byreference.

Each of the cylinders 112 includes an inner circumferential surface 113.The inner circumferential surface 113 is configured to receive the outercylinder 98 of the cushion 12. In this way, the cylinders 112 of theframe 14 receive within them the cylindrical protrusions, including theouter cylinder 98, and thus provide support to the cushion 12.

1.2.1 Reinforcing Rib

The rear side of the bridge 120, i.e. the side facing the patient inuse, may include a reinforcing rib 142 that stiffens, or reduces theflexibility of the bridge 120. The reinforcing rib 142 may preventexcessive pressure from being applied to the face of the patient in theevent the headgear is over tightened. It should be appreciated that thereinforcing rib 142 may be provided on the front side of the frame 14instead of, or in addition to, being placed on the rear side.

1.2.2 Cross Bar

Referring to FIG. 21 , a frame 14 according to another sample embodimentcomprises a cross bar 48 extending between the wing portions 118 and thecylinders 112. The cross bar provides rigidity to the frame 14 andprevents creep of the frame 14 due to repeated bending of the frame 14.

1.2.3 Support Structure/Frame and Headgear Connection

Referring to FIGS. 72C-72I, a patient interface system according toanother exemplary embodiment includes a first indicia 141 on a left sideconnector 138 provided on the wing portion 118 of the frame 14. A secondindicia 143 is also provided on the wing portion 118 and an angle to thefirst indicia 141. As shown in FIGS. 72E-72G, the right side rigidizer22 (FIG. 72F) includes a hole 23 that is configured to receive the rightside headgear connector 139 and the left side rigidizer 22 (FIG. 72G)includes a hole 25 that is configured to receive the left side headgearconnector 138.

The right side headgear connector, or lug, 139 is larger than the hole25 in the left side rigidizer 22. This prevents the left side rigidizer22 from engaging with the right side headgear connector 139 and forcesthe user to assembly the left side rigidizer 22 with the left sideheadgear connector 138.

Referring to FIG. 72H, the left rigidizer 22 may also include an indicia149 in addition to, or in place of, the indicia 143 on the wing portion118 to indicate the correct connection between the left side rigidizer22 and the left side connector portion, or lug, 138.

The first and second indicia 141, 143 may also serve as alignmentindicators to assist the user in correctly connecting the headgear 16 tothe frame 14. As shown in FIG. 72I, an angled connection between theheadgear 16 and the frame 14 may be provided, as shown by the angle 322between the first and second indicia 141, 143 and the rigidizer 22, toincrease the force applied to the nose bridge region of the cushion 12to improve the sealing function of the cushion. As shown in FIG. 72I,the angle may be 20°. However, it should be appreciated that the anglemay be, for example, 2.5°, 5°, 7.5°, 10° or 15°.

1.3 Patient Interface Structure/Cushion

Referring now to FIGS. 3-10 and 20-36 , the cushion 12 may be formedfrom a flexible, elastomeric material, for example silicone, that isdesigned to provide comfort to the patient while forming an adequateseal. The cushion defines an air chamber 26 into which the patient'snose is inserted in use. The cushion 12 locates above the patient'snasal vents and below the patient's nostril openings so that it does notimpinge upon them. This allows a ready flow of air around the airchamber 26 to assist breathing and exhalation.

The cushion 12 may be configured to fit a patient population between theages of, for example, about two to seven years.

The cushion 12 may be generally trapezoidal in shape and has a frontside 28 facing away from the patient, a rear side 30 in contact with thepatient's face in use, a top side 38, a bottom side 40 and two lateralsides 36. The top side 38 of the cushion 12 corresponds to the shorterof the substantially parallel sides of the trapezoid and is the sideclosest to the top of the patient's nose in use. The bottom side 40 ofthe cushion 12 corresponds to the longer of the substantially parallelsides of the trapezoid and is the side closest to the bottom of thepatient's nares in use. The lateral sides 36 of the cushion 12correspond to the non-parallel sides of the trapezoid and are closest tothe patient's nostrils in use. The trapezoidal shape is anatomicallysuitable to allow the cushion 12 to surround the patient's nose withoutobstructing the patient's field of vision. This shape is particularlysuitable for infants and children as they have ‘button’ style noses.This cushion shape allows the cushion to seal along the bridge of thenose which means that the cushion can fit different sizes of noses andtherefore different ages of patients. It should also be appreciated thatalthough in the embodiments depicted the cushion 12 is trapezoidal inshape, it could also be triangular, rectangular, circular or square.

The dimensions of the cushion 12 may be as disclosed in InternationalApplication PCT/AU2008/000270 (WO 2008/106716 A1), the entire contentsof which are incorporated herein by reference. It should be appreciatedthat the dimensions may be otherwise. One reason for the provision ofcushions within these dimensional ranges is that different patients(e.g. infants, children, babies born prematurely, teenagers and adults)present differently sized facial features. In order to provide a “onesize fits all” cushion for patients in the range of 2-7 years of age,the dimensional ratio of length-to-width remains substantially constantwhile the depth changes very little. Children, for example children 2-7years of age, generally have foreheads that protrude further from theface than the nose. During puberty, patient's noses grow more rapidlythan during their preceding years, thus necessitating a mask ofincreased depth.

The facial shape of children, for example children 2-7 years of age,makes it difficult to provide an adult mask with a forehead support thathas just been shrunk or made smaller. In order to maintain the mask onthe patient's face in a sealed position, higher headgear forces arerequired to be applied due to the lack of a forehead support. However,young children still have relatively soft facial bones and thecontinuous application of pressure by the headgear during treatment maydeform the patient's facial bones. This problem may be alleviated bychanging the shape, or form, of the cushion. For example, the cushion(s)described herein may be substituted for a nasal pillows cushion, i.e. acushion having a pair of nasal pillows configured to engage and seal thenares of the patient. As another example, nasal cannulae may be used todeliver the flow of breathable gas.

The rear side 30 of the cushion 12 comprises at least one thin flexiblemembrane 50 (FIG. 6 ) and at least one base wall 52 that connects the atleast one membrane 50 with a dome portion 54 of the cushion 12 (i.e. atthe front side 28 of the cushion 12). In the depicted sampleembodiments, one membrane 50 and one base wall 52 are provided andtogether form part of the lateral sides 36, the top 38 and the bottom 40of the air chamber 26 of the cushion 12.

The word “curvature” as used herein means the angle of a circlesubtended by the membrane 50. A greater curvature allows the cushionmembrane 50 to bend more easily since it rolls more easily. This, inturn, allows a greater degree of compression for a given force (i.e. themembrane 50 is softer). Thus, regions of high curvature have beenincorporated into the top and bottom portions 56 and 60 of the maskcushion 12 which contact sensitive areas of the patients face (i.e.nasal bridge region and region between the patient's nose and mouth).This increases patient comfort and reduces the possibility of pressuresores. The advantage of the thicker bottom portion 60 is that itprovides the mask 10 with greater stability.

In the depicted sample embodiments the base wall 52 is substantiallyaligned to the forward-aft direction of the mask 10 and varies in widtharound the perimeter of the mask 10. The base wall 52, like the membrane50 comprises three main parts: a top portion 62; a bottom portion 64;and two side portions 66. The base wall 52 has a maximum width at itstop and bottom portions 62 and 64. The base wall 52 tapers down to aminimum width at its side portions 66.

The thickness of the side portions 66 of the base wall 52 may berelatively constant. The thickness of the top and bottom portions 62 and64 of the base wall 52 may taper down from a thickness about equal tothe side portions 66 at the base of the base wall 52 to a transitionregion where the base wall 52 transitions into the membrane 50. Thethickened portion 144 of the base wall 52 may serve a positioningfunction as the shape of the thickened portion generally corresponds toshape defined by the wing portions 118 and the arched bridge 120 of theframe 14. For example, as shown in FIGS. 20 and 21 , the shape of thethickened portion 144 of the base wall 52 of the cushion 12 fits betweenthe wing portions 118 and under the arched bridge 120 when the cushion12 is correctly assembled on the frame 14. As the top portion 62 of thethickened portion 144 of the base wall 52 is wider than the bottomportion 64, if the cushion 12 is inserted incorrectly, e.g. upside down,the person assembling the mask will get a tactile indication that thecushion 12 is being improperly attached to the frame 14. The bridge 120also may aid alignment due to the shape of the bridge matching the shapeof raised portion 114.

The cushion 12 may be integrally formed from, for example, silicone orfoam by an injection molding process. The cushion 12 may also be formedby compression molding. The cushion may be formed, for example, bycompression molding a flexible material, for example, silicone rubber.The cushion may be post cured. The cushion 12 may have a hardness of,for example, about 35 to 50, for example about 39 to 45, on the Shore Ahardness scale. As the cushion 12 includes the base wall 52, theaperture 55 in the membrane 50 may be formed in the mold. Alternatively,the aperture 55 may be removed in a post processing step such ascutting. This post processing step could be done in the mold or off themold. The cushion 12 may include a lip or bead 68 on the membrane 50that serves to prevent tearing of the membrane 50 as it is removed fromthe mold.

1.3.1 Membrane

The membrane 50 forms a seal against the adjacent portion of thepatient's face around the patient's nose while the base wall 52 elevatesthe front side 28 of the cushion 12 above the patient's nose. Thisallows pressurised air (e.g. CPAP therapy) to be delivered to thepatient. Although one membrane is shown, it should be appreciated thatthe cushion 12 may be a double membrane cushion, or that any number ofmembranes greater than one may be provided.

As shown in FIG. 7 , the end of the membrane 50 may be provided with alip or bead 68 to reduce, or minimize, tearing of the membrane 50, forexample during demolding of the cushion 12 as described in more detailbelow. The lip 68 may be, for example, about 0.10 to 0.20 mm wide, forexample about 0.15 mm wide.

As shown in FIGS. 6 and 7 , the cushion 12 may consist of a singlemembrane 50 having a thickness in the sealing area that may vary from,for example, about 0.10 to 0.70 mm, for example about 0.20 to 0.58 mm.The cushion 12 provides a comfortable seal on the face of the patientwith a minimum force.

The membrane 50 defines an aperture 55 (FIG. 4 ) for receiving thepatient's nose. The shape of the aperture 55 is similar to the shape ofthe cushion 12. The dimensions of the aperture 55 may be as disclosed inInternational Application PCT/AU2008/000270 (WO 2008/106716 A1), theentire contents of which are incorporated herein by reference. It shouldbe appreciated that the dimensions may be otherwise.

The membrane 50 generally has three portions, each having a differentcross-sectional shape. A top portion 56 is located substantially overthe patient's nasal bridge in use, two side portions 58 are locatedsubstantially at either side of the patient's nares in use, and a bottomportion 60 is located substantially under the patient's nose in use. Theexterior dimensions of the membrane 50 from a rear perspective are thesame as the corresponding overall dimensions of the cushion 12 asdetailed above.

The cross-sections of each of these three portions 56, 58 and 60 of themembrane 50 are generally C-shaped but they vary with respect to radius,curvature and material thickness. By way of a general comparison, thetop and bottom portions 56 and 60 have a larger curvature or roll thanthe side portions 58 and the bottom portion 60 is thicker than the top56 and side portions 58.

Referring to FIG. 79 , the cushion 12 may include a membrane 51 that isincreased in length compared to the membrane 50 shown in FIG. 6 . Theincreased membrane length provides sealing contact between the membrane51 and the face of the patient over a larger surface area and is morestable. The increased length of the membrane 51 also prevents disruptionof the seal if the child moves the cushion, for example, during sleep.Furthermore, the increased length of the membrane 51 prevents or reducesthe likelihood of the cushion inverting which would make it difficult toseal the cushion on the patient.

1.3.2 Cushion Transparency

In one sample embodiment, the cushion 12 is substantially transparent orwater clear such that a parent or clinician can inspect the patient'snares. This is particularly useful in the case of children to ensurethat there are no physical obstructions to nasal breathing (e.g. mucus).Additionally, a clear path of sight may also assist in fitting the maskto the patient by a third party (for example, nurse or parent). In othersample embodiments, the cushion 12 is translucent or frosted so that anyobvious obstructions to breathing can still be identified and rectified.The membrane 50 may be translucent or frosted also, or the membrane 50may be clear or transparent. The membrane may also have a polishedfinish which provides increased friction against the face of thepatient, to assist in maintaining a seal between the membrane 50 and thepatient's face.

1.3.3 Vent

The cushion 12 includes an exhalation vent 72 in the form of two arrays74 and 76 of apertures 78 disposed along respective parallel rows. Theapertures 78 are provided in the thickened portion 144 of the base wall52 of the cushion. The arrays 74, 76 of vent holes 78 provide apredetermined vent flow from the cushion 12 when the cushion 12 issealed with the elbow 18 and the plug 20. The parallel rows of ventapertures also facilitate tooling of the machinery for forming thecushion. It should be appreciated that other known venting arrangementscould be incorporated into the cushion 12 and frame 14 of therespiratory mask assembly 10. The vent holes 78 may have a diameter of,for example, about 1.50 mm or about 1.60 mm. It should be appreciatedthat the diameter of the vent holes may be other than as shown anddescribed.

1.3.4 Cushion Orientation

The front surface 28 of the cushion 12 may also include at least oneorientation element, such as indicia 70 that is/are configured toindicate the correct direction or orientation for assembling the cushion12 with the frame 14. As shown in FIG. 3 , the indicia 70 may beprovided adjacent the arrays 74, 76 of vent holes 78. However, it shouldbe appreciated that the indicia may be provided at another portion ofthe cushion 12.

Referring to FIG. 10 , according to another embodiment of thetechnology, the cushion 12 may comprise other orientation elements suchas a lug, or lugs 156 that are configured to be engaged in a hole orholes, on the frame 14 to indicate correct assembly of the cushion 12with the frame 14.

Referring to FIGS. 20 and 21 , the thickened portion 144 of the basewall 52 may serve a positioning function as the shape of the thickenedportion generally corresponds to shape defined by the wing portions 118and the arched bridge 120 of the frame 14. For example, as shown inFIGS. 20 and 21 , the shape of the thickened portion 144 of the basewall 52 of the cushion 12 fits between the wing portions 118 and underthe arched bridge 120 when the cushion 12 is correctly assembled on theframe 14. As the top portion 62 of the thickened portion 144 of the basewall 52 is wider than the bottom portion 64, if the cushion 12 isinserted incorrectly, e.g. upside down, the person assembling the maskwill get a tactile indication that the cushion 12 is being improperlyattached to the frame 14.

Referring to FIG. 78 , a patient interface according to another sampleembodiment includes a frame 14 and a cushion 12. The shoulders 92 of thecushion 12 are configured to engage the frame 14 to secure the cushion12 to the frame 14. The exhalation vents 72 of the cushion 12 may beprovided in a thickened portion 144 of the cushion so that the vents cannest or slot into an aperture 214 provided in the frame 14. Thisassembly provides an extra visual and/or tactile cue for correctassembly of the cushion 12 to the frame 14. The thickened portion 144 ofthe cushion and the aperture 214 provided in the frame 14 thus provideanother orientation element.

Referring to FIGS. 123-128 , a patient interface system according toanother sample embodiment may comprise a cushion 12 having at the ventregion thickened portion 145 of the base wall 52 to increase the lengthof the vent holes 78, 79. The vent holes 78, 79 may have an aspect ratioof 1.6/5.0, or 0.32. The thickened portion 145 of the cushion 12 alsoaids in aligning the cushion with the frame 14 as the thickened portion145 of the cushion 12 extends past the bridge 120 and the crossbar 48 ofthe frame 14, as shown in FIGS. 126-128 . Referring to FIGS. 123 and 124, the vent apertures or holes 78, 79 may be configured to provide a ventflow within 30.7 to 41.0 L/min at 12 cm of H₂O. Referring to FIG. 126 ,the cushion 12 may include a parting line 13 which separates the sealingarea from the remainder of the cushion. The sealing area of the cushionmay be polished to improve the sealing function of the cushion with thepatient's face.

1.3.5 Connection between Cushion and Air Delivery Tube

Advantageously, the mask 10 also provides a connection arrangement 100(FIGS. 20 and 21 ) between the cushion 12 and air delivery tube 22 thatat least partially decouples movement of the tube 22 from the cushion 12and support structure 14. This means that lateral and some axialmovement of the tube 22 (e.g., from tube drag) and tube rotation do notsubstantially move the cushion 12. Subsequently, movement of the cushion12 and support structure, or frame, 14 on the patient's face due to tubedrag is reduced. This serves to reduce disturbance to the patient,particularly as it aids maintenance of the cushion seal with thepatient's face. The connection arrangement 100 comprises two parts: thecylindrical protrusions 88 and the elbow 18, as shown in FIGS. 15, 20and 21 .

The cushion 12 has a short, hollow cylindrical protrusion 88 extendingfrom each of its lateral sides 36 for receiving an elbow 18 or plug 20.The hollow 90 of each protrusion 88 is in fluid communication with theair chamber 26 of the cushion 12. In this case, the dimensions of thehollows 90 are the same such that the elbow 18 and plug 20 can be fittedinto either hollow 90. This allows the elbow 18 and air delivery tube 2to connect to the most convenient side of the mask 10. With such anarrangement, the patient may lie on their stomach with their head facingto one side without occluding the air delivery tube by placing the plug20 in the hollow 90 on the side of the mask corresponding to the sidethe patient's head is lying on. Additionally, a line of sight to thepatient's nose is possible as there is no elbow or air delivery tubepositioned on the front of the mask as with other breathing masks. Ifthe cushion is not water clear and thereby prevents the clinician fromseeing the patient's nose, it is still possible to see if the patient isin distress as the mouth is uncovered i.e. the lips may begin to turnblue.

The elbow 18 is releasably and rotatably connected to the cushion 12 andthe air delivery tube 2. Each cylindrical protrusion 88 comprises aninner cylinder 96 and an outer cylinder 98 that are substantiallyconcentric and joined at an end closest to the support structure 14 by athin flexible cylindrical membrane 102, as shown in FIGS. 9 and 10 . Thedesired and suitable dimension ranges for the inner and outer cylinders96 and 98 may be as provided in International ApplicationPCT/AU2008/000270 (WO 2008/106716 A1), the entire contents of which areincorporated herein by reference. It should be appreciated that thedimensions may be otherwise.

By virtue of the flexibility and elastic properties of the thin membrane102, the inner cylinder 96 can rotate laterally with respect to theouter cylinder 98, about the thin membrane 102, by a small angle, andalso move axially with respect to the outer cylinder 98 by a smalldistance. In the depicted sample embodiment, the maximum angle ofrotation and the axial displacement may be as described in InternationalApplication PCT/AU2008/000270 (WO 2008/106716 A1), the entire contentsof which are incorporated herein by reference. It should be appreciatedthat the angle and displacement may be otherwise. Thus, the innercylinder 96 is substantially decoupled from the outer cylinder 98. Inthe depicted sample embodiment, the thin membrane 102 is made fromsilicone, but it should be appreciated that it could be made from anyother suitable material that is flexible and biocompatible.

To aid in further decoupling tube drag, a highly flexible tube may beattached to elbow 18. For example, a tube as disclosed in US patentapplication US 2009/0078259, the entire contents of which areincorporated herein by reference.

The outer diameter of the elbow 18 forms a snug fit with the innerdiameter of the inner cylinder 96. The inner cylinder 96 includes acircumferential rib 104 on its inner surface 106 (see FIG. 9 ) that isconfigured to mate with a cooperating circumferential groove 108disposed on the outer surface 110 of the elbow 18. Accordingly, when theelbow 18 is inserted into the soft inner cylinder 96, the rib 104interlocks with the groove 108 to axially fix the elbow 18 in the innercylinder 96. By virtue of the fact that the inner cylinder 96 issubstantially decoupled from the outer cylinder 98, the elbow 18 and airdelivery tube 2 are substantially decoupled from the cushion 12. Inanother sample embodiment, the rib 104 and groove 108 arrangement couldbe reversed (i.e. rib 104 on elbow 18, groove 108 on inner cylinder 96).

The free end of the outer cylinder 98 is angled by an angle A towardsthe center of the front side of the mask 10 so that a portion of theinner cylinder 96 extends beyond the end of the outer cylinder 98. Thisallows the inner cylinder 96 to be laterally displaced towards the frontside of the mask 10 to a greater degree since it is not blocked by theouter cylinder 98 to the same extent. This provides better decoupling ofthe tube 2 from the cushion 12. Another advantage is that this angleprovides the mask with better aesthetics, in that the mask appears morestreamlined to the face. The angle may be as disclosed in InternationalApplication PCT/AU2008/000270 (WO 2008/106716 A1), the entire contentsof which are incorporated herein by reference. It should be appreciatedthat the angle may be otherwise.

The decoupling mechanism is also supported by the frame 14 since theouter cylinders 98 of the cushion 12 are snugly seated in respective,relatively cylinders 112 provided in the support structure 14.

1.3.6 Assembly of Cushion to Frame and Elbow

The cushion 12 is assembled to the frame 14 by inserting each short,hollow cylindrical protrusion 88 through the respective cylinder 112 ofthe frame 14 as shown in FIG. 8 . Each short, hollow cylindricalprotrusion 88 comprises the inner cylinder 96 and the outer cylinder 98,which are connected by the thin membrane 102. The cushion 12 has abearing diameter 128 that is chosen to provide a balance between ease ofassembly of the cushion 12 with the frame 14 and restricted rotationalmovement of the cushion 12 when assembled into the cylinders 112 of theframe 14.

The elbow 18 is assembled to the cushion 12 by inserting the elbow 18into the inner cylinder 96 as shown in FIG. 15 . The outer surface 110of the elbow 18 comprises a circumferential groove 108 that receives acircumferential rib 104 (FIG. 8 ) of the membrane 102 of the cushion 12.The circumferential rib 104 and the circumferential groove 108 providean interference fit that seals the connection between the elbow 18 andthe cushion 12. The inner surface 106 of the inner cylinder 96 may alsoengage the outer surface 110 of the elbow 18 to provide a sealingsurface as shown in FIG. 15 .

Lug or bead 92 on cushion 12 may be adapted to engage with the frame 14to maintain the cushion and frame assembly.

1.3.7 Valve

Referring to FIGS. 37-40 , a cushion and respiratory mask assemblyaccording to another sample embodiment includes a valve 146 in eachinner cylinder 96 of each short, hollow cylindrical protrusion 88 of thecushion. The valve 146 may be integrally formed with the cushion 12 andinclude a plurality of individual flaps 147 that are “closed” (incontact with each other) to seal the inner cylinder 96 when a positivepressure (i.e. pressurized flow of breathable gas) is applied to themask. As shown in FIG. 38 , the flaps 147 are “open” when the elbow 18is inserted into the inner cylinder 96 to deliver the flow of gas. Asshown in the drawings, each valve 146 includes six flaps 147. It shouldbe appreciated that the valves may include any number of flaps.

The provision of the valves 146 in the cushion eliminates the need for aplug to seal the side of the cushion opposite the elbow, thus reducingparts, inventory, and costs. It also reduces the need for smallcomponents (such as a plug) that a child could choke on. The provisionof the valves 146 also assists in assembling the mask and reducesassembly errors. For example, machine vision equipment configured todetect correct assembly of masks on a production assembly line mayincorrectly conclude that a plug is properly inserted when the plug isimproperly inserted into the cushion. The provision of the valves 146 inthe cushion 12 eliminates such errors.

Referring to FIGS. 41 and 42 , the inner cylinder of the hollowprotrusion of the cushion 12 may be provided as a conical inner cylinder150. The tapered opening of the conical cylinder 150 aids insertion ofthe elbow 18 or plug 20 into the cushion 12. A recess 148 may beprovided between the flaps 147 of the valve 146 and the conical cylinder150 to provide a seal at the contacting surfaces of the elbow 18 and theflaps 147 as shown in FIG. 42 .

Referring to FIGS. 43 and 44 , according to another sample embodimentthe valve 152 may be similar to an anti-asphyxia valve (AAV) that issealed at pressure by the flow F of breathable gas in the cushion. A lipseal 154 may be provided to seal the end of the elbow 18 when the elbow18 is inserted into the cushion.

1.3.8 Plug

The cushion 12 has a short, hollow cylindrical protrusion 88 extendingfrom each of its lateral sides 36 for receiving an elbow 18 on one sideand a plug 20 on the other side. As shown in FIG. 1 , the plug 20 mayhave a handle 21 that is adapted to be gripped by a user, to be pulledout of or pressed into one of the cylindrical protrusions 88 of thecushion 12.

As illustrated in FIG. 9 , the outer surface 110 of the plug 20comprises a circumferential groove 108 that receives the circumferentialrib 104 of the thin membrane 102 of the cushion 12. The circumferentialrib 104 and the circumferential groove 108 provide an interference fitthat seals the connection between the plug 20 and the cushion 12. Theinner surface 106 of the inner cylinder 96 may also engage the outersurface 110 of the plug 20 to provide a sealing surface.

The plug 20 may include a beveled flange 116 that is configured to aidinsertion of the plug 20 into the short, hollow cylindrical protrusion88 of the cushion 12. As shown in FIG. 9 , a circumferential edge 114 isprovided between the outer sealing surface 110 of the plug 20 and theouter surface 122 of the plug 20. The inner cylinder 96 of the short,hollow cylindrical protrusion 88 of the cushion 12 is captured betweenthe beveled flange 116 and the circumferential edge 114 to providesecure attachment of the plug 20 to the cushion 12. Preferably, the plugis more easily gripped by an adult than by a child.

Referring to FIG. 71 , in an alternative sample embodiment of thepresent technology, the plug 202 may include a handle 210 to assist ininserting and removing the plug from the cushion of the patientinterface. The handle 210 may extend from a top surface of the plug 202,and be adapted for gripping by a user. For example, the handle 210 mayextend a predetermined distance from an end of the plug 202 and beshaped for ease of gripping by the user.

The plug 202 is configured to seal to the cushion with substantially noleak. The plug 202 is adequately retained to the cushion at pressures upto, for example, about 40 cm H₂O. The plug 202 provides ease of assemblyand disassembly to and from the left and right side of the cushion,depending on which side the patient connects to the air delivery tube.

Referring to FIGS. 45-47 , a cap 158 may be provided with a valve 160.As shown in FIGS. 45 and 46 , the valve 160 may be similar to the valve152 shown in FIGS. 43 and 44 . It should be appreciated that the valve160 may be similar to the valve 146 shown in FIGS. 37-42 . The cap 158may be preassembled with the valve 160 and the cap may then be insertedinto the cushion 12. The cap 158 may include a groove 162 configured tosnap fit the cap 158 into the frame 14 and prevent the cap 158 frombeing inserted too far into the hollow cylindrical protrusions 88 of thecushion 12. The cap 158 could also be molded into the frame 148, forexample by a living hinge. The cap 158 is adapted to receive and retainthe elbow 18, at which time the valve 160 is opened.

1.3.8.1 Tether

Referring to FIGS. 48-54 , an alternative plug or cap 170 adapted toconnect to a tether may include a groove 172 in its outer surface. Atether 164 may include a ring 166 at one end configured to be receivedin the groove 172 and a connector 168 at an opposite end for connectionof the tether 164 to the frame 14. An alternate configuration of theconnector 168 is shown in FIG. 51 . The groove 172 allows rotation ofthe cap 170 with respect to the ring 166 for easier orientation of thecap 170. The tether 164 may be formed of, for example, PTFE, nylon,polycarbonate.

FIG. 52 depicts a connecting structure 178 provided on the frame 14 thatis configured to receive the connector 168 of the tether 164 to connectthe tether 164 to the frame 14. FIG. 53 depicts a connector 180 of thetether 164 according to another sample embodiment that snap fits intoplace on the frame 14 to connect the tether 164 to the frame. FIG. 54depicts the connector 168 of the tether 164 molded into the frame 14.

Referring to FIGS. 69 and 70 , a plug 202 for the cushion may comprisean integrally formed tether 204. The end of the tether 204 may includeretention lugs 206 for securing the plug 202 to the frame. As shown inFIGS. 73-77 , the retention lugs 206 are inserted through an aperture211 in the frame 14 of the patient interface to permanently retain theplug 202 to the frame 14.

Referring back to FIG. 70 , a rib 208 may be provided adjacent theretention lugs 206. As shown in FIG. 72A, the frame 14 of the patientinterface may include a guide or cap 212 to prevent the tether 204 frombeing rotated upwards past the horizontal end to prevent the plug 202from interfering with the user's eyes. The rib 208 is configured tolocate the end of the tether 204 in the aperture 211 of frame 14 so thatthe tether does not move laterally when positioned within the aperture211.

As shown in FIG. 72B, a stopper 213 may be included on the frame 14. Thestopper 213 prevents the tether 204 from being positioned downwards toprevent the tether 204 from being positioned over the array of ventholes 74, 76, which could cause noise from the vented gases hitting thetether 204.

Referring to FIGS. 73-77 , the retention lugs 206 may be formed toprovide a one way fit of the plug to the frame 14 of the patientinterface. The lugs 206 may be angled upwardly as shown in FIG. 73 withrespect to the tether 204. Alternatively, the lugs 206 may have a firstsurface facing 207 facing the lower surface of the tether 204, and asecond surface 209 facing away from the lower surface of the tether 204,where the first surface 207 is substantially parallel to the lowersurface 205 of the tether 204, and the second surface 209 is angled withrespect to the lower surface 205 of the tether, as shown in FIG. 74 . Itshould be appreciated that other permanent attachment or one way fitmechanisms may be provided for securing the plug 202 to the frame 14 viathe tether 204.

The plug 202 is adapted to be permanently retained to the frame 14 bythe tether 204 and the retention lugs 206 so as to not pose a chokinghazard for a child.

The plug 202, the tether 204, the retention lugs 206 and the rib 208 maybe integrally formed of, for example, polypropylene, nylon,polycarbonate, polyurethane, or silicone. It should be appreciated thatother materials may be used to form the plug, tether, retention lugs,and rib.

Referring to FIGS. 92-94 , a tether 220 may be connected to a plug 216.The plug 216 may include a handle 218, and the tether 220 may be adaptedto connect to the handle 216. The tether 220 may include a recess 232,formed between flanges 228 and 230, and a rounded portion 226. Therecess 232 is adapted to receive the handle 218 of the plug 216, withthe flanges 228 and 230 sandwiching the handle 218. The rounded portion226 is adapted to conform to the rounded side portion of the plug 216.

The tether 220 may also include a connector 222 having an aperture 224,the connector being adapted to connect to the frame 14. The aperture 222is configured to receive the frame 14, so the tether 220 is connected tothe frame, with the plug 216 connected to the tether 220. When the plug216 is removed from the cushion 12, the tether 220 will hold the plug216 so that the plug 216 does not become lost or a choke hazard.

The tether 220 may be formed from molded silicone that is stretchable.The loop of the tether 220 that contains the aperture 224 may bestretched to fit over the wider part of the frame 14, and allowed to beretained on the bridge portion 223 of the frame 14. When plug 216 isremoved from the cushion 12 while connected to the tether 220, the plugwill not be lost because it is connected to the frame 14 by the tether220.

Referring to FIGS. 95 and 96 , the frame 14 may include an aperture 234on the cylinders 112, adapted to connect tether 238 to the frame 14. Thetether 238 may include a connector in the form of a protrusion 240adapted to fit within the aperture 234. The protrusion 240 may beadapted to be permanently held within the aperture 234, or may beadapted to be temporarily held within the aperture 234, such as throughthe use of a retaining mechanism. When the plug 236 is removed from thecylinder 96 of the cushion 12, the tether 238 connects the plug 236 tothe frame 14. The protrusion 240 may be adapted to turn within theaperture 234 so that the plug 236 and the tether 238 may be pushed toconnect in either side of the cushion.

One aperture 234 may be located on each cylinder of the frame 14. Wherethe protrusion 240 is removable from the aperture 234, the tether 238and the plug 236 may be moved between either side of the frame 12. Wherethe protrusion 240 is adapted to be permanently held within the aperture234, the frame may be provided with two tethers 238, each connected to aplug 236. Either one of the plugs 236 could be connected within thecorresponding cylinder 96 of the cushion 12, while the other cylinder 96would be connected to the elbow.

Referring to FIGS. 97-99 , plug 248 may be connected to tether 250.Tether 250 may include connector 252, which is adapted to be received inaperture 242. Connector 252 includes a wide portion 254, and aperture242 includes a narrow portion 246 and a wide portion 244. The wideportion 254 of the connector 252 may be received by the wide portion 244of the aperture 242, and the wide portion 254 of the connector 252pushed below a lower surface of the cylinder 112, and the connector 252may be positioned so that the wide portion 254 is below the narrowportion 246 of the aperture 242, to retain the tether 250 to thecylinder 112 of the frame 14. The tether 250 may be stretchable to allowthe connector 252 to stretch to reach the wide portion 244 of theaperture 242.

Referring to FIGS. 100-102 , plug 262 may be connected to tether 264,with tether 264 adapted to connect to the frame 14. The tether 264 mayinclude a connector 266, with a wide portion 268. The cylinder 112 ofthe frame 14 includes an aperture 270 having a wide portion 272 and anarrow portion 274. The wide portion 268 of the connector 266 is sizedto fit into the wide portion 272 of the aperture 270. The wide portion268 of the connector 266 may be pushed below a lower surface of thecylinder 112, and the connector 266 may be positioned so that the wideportion 268 is below the narrow portion 274 of the aperture 270, toretain the tether 264 to the cylinder 112 of the frame 14. The tether264 may be stretchable to allow the connector 266 to stretch to reachthe wide portion 272 of the aperture 270. Alternatively or in addition,the cushion 12 may be compressible or flexible to permit the plug 262 tomove while connected to the cushion 12, such that connector 266 maytravel from the narrow portion 274 to the wide portion 272 of theaperture 270.

Referring to FIG. 103 , an alternate configuration is illustrated, inwhich the aperture 270 includes a wide portion 272 and a narrow portion274. The wide portion 272 may be offset to the side from the narrowportion 274 with respect to an axis of cylinder 96. The offset helps toretain the connector 266 in the narrow portion 274 of the aperture 270.

Referring to FIGS. 104 and 105 , plug 276 is adapted to fit within thecylinder 96 of cushion 12. The plug 276 includes a handle 278 and aconnector 282 for connecting the plug to the frame 14 via post 290.

The handle 278 includes ribs 280 adapted to be gripped by a user. Theconnector 282 includes aperture 284 having a large aperture portion 285and a small aperture portion 287.

The post 290 is located on the headgear connector 288. The post 290includes a head 292 that has a diameter that is smaller than thediameter of the large aperture portion 285 but larger than the diameterof the small aperture portion 287, so that the head 292 of the post 290can fit within the large aperture portion 285, but the head 292 of thepost can be retained by the small aperture portion 287, as illustratedin FIG. 105 .

Referring to FIGS. 107 and 108 , the post 294 has a connector 298adapted to retain the plug 216. The connector 298 includes flanges 228and 230 and recessed groove 232, adapted to receive the handle 218 ofplug 216. Post 294 may constructed in one piece with cushion 12.

Referring to FIGS. 106, 109 and 110 , plug 300 may be placed in cylinder96 of cushion 12. When the plug 300 is removed from the cylinder 96, theplug 300 may be connected to connector 304, which is attached to frame14 via post 302, as shown in FIG. 110 . The connector 304 has anaperture 306, which is adapted to receive the plug 296, with the groove301 of plug 300 adapted to receive an inner circumferential edge 305 ofthe connector 300.

1.3.9 Port

Referring to FIGS. 55-68 , a port 182 may be provided to one of thehollow cylindrical protrusions 88 of the cushion 12 to measure pressureor to administer breathable gas, for example oxygen. The port 182 mayoperate as a luer port. As shown in FIGS. 57 and 58 , the port 182 maybe connected to a wing portion 118 of the frame by an extension member186 having a barb 184 received in a slot 187 in the wing portion 118.Alternatively, as shown in FIGS. 59 and 60 , the port 182 may beconnected to the wing portion 118 by a slot 188 in the extension member186 that is received by a hook 174 on the rear side of the wing portion118.

According to another sample embodiment shown in FIGS. 61 and 62 , theextension member 186 includes a slot 188 and a hole 190. The slot 188 isreceived by a connector 138 of the frame 14 and the hole 190 is passedover a capped post 192 that is provided on the forward finger 130 of thereinforcing structure 22.

As shown in FIGS. 63 and 64 , the extension member 186 may include aslot 188 that secures the extension member 186 between the wing portion118 of the frame 14 and the forward finger 130 of the reinforcingstructure 22.

The port 182 may also be attached to the frame by a tether, for examplea VELCRO® strap 194, as shown in FIG. 65 .

FIGS. 66-68 depict a port 182 according to other sample embodiments. Theport may include a snap arm 196 as shown in FIG. 66 , or two snap arms196 as shown in FIG. 67 , that include a snap 198 at the end of eachsnap arm 196. The snap(s) 198 is (are) received in a slot(s) 200 asshown in FIG. 68 to secure the port 182 to the frame 14.

Referring to FIGS. 111 and 112 , a pressure port 182 may be provided tothe patient interface system. A pressure tube 312 (FIG. 113 ) may beattached to the outlet 183 of the pressure port 182 and to a pressuremonitoring device so that pressure in the patient interface system canbe determined. To prevent the pressure port 182 from being a chockinghazard for pediatric patients, the pressure port 182 may be connected tothe patient interface system by a tether 310. As shown in FIG. 111 , thetether 310 may include a loop portion 324 that is provided around theelbow 18 connected to the air delivery tube 2 to prevent the pressureport from being disconnected from the patient interface system. Althoughthe looped portion 324 of the tether is shown as extending around theelbow 18, it should be appreciated that the looped portion 324 mayextend around a headgear strap 4, the frame 14, or any other componentof the patient interface system. The tether 310 has a snap 326 thatsnaps into the pressure port 182 around the outlet 183 of the pressureport 182 as shown in FIG. 112 .

Referring to FIG. 113 , according to another sample embodiment, thepressure port 182 may be permanently affixed to the pressure tube 312 byan adaptor 320 to prevent the pressure port 182 from being a chokinghazard for pediatric patients.

Referring to FIGS. 114-116 , the pressure port 182 may be attached to aheadgear strap, for example side strap 4, and/or a rigidizer 22 of theheadgear 16. As shown in FIGS. 115 and 116 , the pressure port 182 maybe connected by a tether 314 that includes a post 328 that extendsthrough the rigidizer 22 and the side strap 4. The pressure port 182,and the tether 314, may be provided on a side of the patient interfacesystem on which the patient is not usually sleeping in order to improvecomfort.

Referring to FIGS. 117 and 118 , the pressure port may take the form ofan adaptor 330 provided between the cushion and the elbow. The adaptor330 has an outlet 334 for connection with a pressure measuring tube. Theadaptor 330 may be retained to the patient interface system by a collar316 that is coupled around another component, such as the elbow 18 ofthe air delivery tube 2. The collar 316 is connected to the adaptor 330by a tether 332.

Referring to FIGS. 119-122 , a pressure port 308 according to anothersample embodiment may be secured to a pressure tube 312 by a collar 336that is coupled around the pressure tube 312. The pressure port 308 isconnected to the collar 336 by a tether 338 and a snap 340. The collar336 may also function as a retainer for the tube 312, which may also beused as a means for delivering supplemental gas, such as oxygen.

Referring to FIGS. 120-122 , the pressure port 308 includes a firsttapered end 342 configured for insertion into a cylinder of the cushion12 of the patient interface system. A second end 344 of the pressureport 308 is configured to be connected to the pressure tube 312 formonitoring a pressure inside the patient interface system. As shown inFIG. 122 , the second end 344 of the pressure port 308 has a taperedsurface for insertion into the pressure tube 312. The tapered surface344 may also be polished and free from flash to facilitate insertion andremoval of the second end of the pressure port 308 into the pressuretube 312.

1.4 Elbow and Tube

Referring to FIGS. 11-15 , the elbow 18 provides a sealed but removableconnection with the cushion 12. As shown in FIG. 11 , the elbow 18provides a sealed and permanent connection with the tube 2. Thestructure of the elbow 18 that fits within the cushion 12 may beidentical to the corresponding structure of the plug 20, and likereference numerals are accordingly used. The elbow 18 includes a tubeconnection end 124 configured to connect the elbow 18 to the tube 2. Thetube 2 may be a retractable tube as disclosed in, for example, U.S.Patent Application Publication 2009/0078259 A1, the entire contents ofwhich are incorporated herein by reference. The tube 2 may have a lengthof about 2 m or less. The use of a retractable tube having a length ofabout 2 m or less reduces the impedance of the tube.

The elbow 18 includes a beveled flange 116 that is configured to aidinsertion of the elbow 18 into the short, hollow cylindrical protrusion88 of the cushion 12. As shown in FIG. 15 , a circumferential edge 114is provided between the outer sealing surface 110 of the elbow 18 andthe outer surface 122 of the elbow 18. The inner cylinder 96 of theshort, hollow cylindrical protrusion 88 of the cushion 12 is capturedbetween the beveled flange 116 and the circumferential edge 114 toprovide secure attachment of the elbow 18 to the cushion 12.

Referring to FIG. 14 , the elbow may have a bend, or angle, 126 in therange of, for example, about 35° to 55°, for example about 39.5° to49.5°. The elbow 18 may have an inner diameter d1 of, for example, about7 to 10 mm, for example about 8.5 mm.

1.5 Alternate Embodiments

It should be appreciated that the mask or patient interface system mayhave other interfacing arrangements, e.g., over-the-nose interface,full-face, nasal prongs, pillows, or cannulae, or a combination of amouth sealing structure in combination with nasal prongs, pillows, orcannulae.

The respiratory mask assembly may be configured so that no hard materialis exposed. For example, the support structure and or the rigid membersmay be covered in a material that is softer than the material used toform the support structure and/or the rigid members. In the sampleembodiments discussed above in which the cushion and the frame, orsupport structure, are formed as a single piece, e.g. by co-molding, thesupport structure may be formed to be more rigid than the cushion, butless rigid than currently used mask frames or shells made of rigidplastic material.

While the technology has been described in connection with what arepresently considered to be the most practical and desirable embodiments,it is to be understood that the technology is not to be limited to thedisclosed embodiments, but on the contrary, is intended to cover variousmodifications and equivalent arrangements included within the spirit andscope of the invention(s). Also, the various embodiments described abovemay be implemented in conjunction with other embodiments, e.g., aspectsof one embodiment may be combined with aspects of another embodiment torealize yet other embodiments. Further, each independent feature orcomponent of any given assembly may constitute an additional embodiment.In addition, while the technology has particular application to patientswho suffer from OSA, it is to be appreciated that patients who sufferfrom other illnesses (e.g., congestive heart failure, diabetes, morbidobesity, stroke, barriatric surgery, congenital disease in childrenetc.) can derive benefit from the above teachings. Moreover, the aboveteachings have applicability with patients and non-patients alike innon-medical applications.

What is claimed is:
 1. A patient interface configured to deliverpressurized breathable gas to a patient's airways, the patient interfacecomprising: a flexible cushion arranged to interface with and deliverair to a nose of the patient in use, the flexible cushion comprising apair of air inlets on opposite lateral sides of a central portion of theflexible cushion, each air inlet having a circumferential flangepositioned around an outer surface of said air inlet to form acircumferential channel with the central portion of the flexiblecushion; a frame that is more rigid than the flexible cushion and isconfigured to support the flexible cushion, the frame comprising a pairof lateral portions, each lateral portion comprising a receptacle thatreceives a respective one of the air inlets and each lateral portion ofthe frame being received in a respective one of the circumferentialchannels around the air inlets; and a removable pressure portconnectable to a pressure monitor configured to determine the pressureof the breathable gas, wherein each air inlet is configured to beselectively coupled to either the removable pressure port or an airdelivery tube, and wherein the removable pressure port is configured sothat when the removable pressure port is coupled to a respective one ofthe air inlets, the respective air inlet is prevented from receivingpressurized breathable gas from the air delivery tube.
 2. The patientinterface of claim 1, wherein each air inlet is self-sealing andcomprises a sealing valve that is configured to be opened by theinsertion of the air delivery tube into the air inlet.
 3. The patientinterface of claim 2 wherein the sealing valve is integrally formed withthe flexible cushion.
 4. The patient interface of claim 2, wherein thesealing valve comprises a plurality of flaps.
 5. The patient interfaceof claim 4, wherein the flaps are hinged.
 6. The patient interface ofclaim 2, wherein the sealing valve is biased to the closed position. 7.The patient interface of claim 1, wherein the flexible cushion and theframe are separable from each other.
 8. A patient interface assemblyconfigured to pressurized breathable gas to a patient's airways, thepatient interface assembly comprising: the patient interface of claim 1;and the air delivery tube.
 9. A patient interface configured to deliverpressurized breathable gas to a patient's airways, the patient interfacecomprising: a flexible cushion arranged to interface with and deliverair to a nose of the patient in use, the flexible cushion comprising apair of air inlets on opposite lateral sides of a central portion theflexible cushion, each air inlet having a circumferential flangepositioned around an outer surface of said air inlet to form acircumferential channel with the central portion of the flexiblecushion; a frame that is more rigid than the flexible cushion and isconfigured to support the flexible cushion, the frame comprising a pairof lateral portions, each lateral portion comprising a receptacle thatreceives a respective one of the air inlets and each lateral portion ofthe frame being received in a respective one of the circumferentialchannels around the air inlets, the frame further comprising an upperbridge and a lower bridge extending between the air inlets, the lowerbridge being positioned to resist movement of the air inlets toward eachother; and a removable pressure port that is connectable to a pressuremonitor configured to determine the pressure of the breathable gas,wherein each air inlet is configured to be selectively coupled to eitherthe removable pressure port or an air delivery tube so that one of theair inlets is coupled to the removable pressure port while the other airinlet is coupled to the air delivery tube.
 10. The patient interface ofclaim 9, wherein the removable pressure port is a luer port.
 11. Thepatient interface of claim 9, wherein the removable pressure port isconfigured to receive a supply of breathable gas from a source outsideof the patient interface.
 12. The patient interface of claim 9, whereinthe removable pressure port is attached to the frame by way of a tether.13. The patient interface of claim 9, further comprising a pressure tubeattached to the removable pressure port, the pressure tube beingattachable to the pressure monitor.
 14. The patient interface of claim13, wherein the pressure tube is permanently attached to the removablepressure port.
 15. The patient interface of claim 9, further comprisingheadgear attachable to the frame and configured to support the flexiblecushion and the frame on the patient's head.
 16. The patient interfaceof claim 15, wherein the removable pressure port is attached to theheadgear by way of a tether.
 17. The patient interface of claim 15,wherein the headgear comprises a rigidizer.
 18. The patient interface ofclaim 9, wherein the flexible cushion and the frame are separable fromeach other.
 19. A patient interface assembly configured to pressurizedbreathable gas to a patient's airways, the patient interface assemblycomprising: the patient interface of claim 9; and the air delivery tube.20. The patient interface of claim 19, wherein the air delivery tube andthe removable pressure port are configured to be interchangeably coupledto each air inlet.
 21. The patient interface of claim 9, wherein thepair of air inlets are self-sealing with each air inlet comprising asealing valve configured to automatically close the air inlet when theinterior of the air inlet is empty.
 22. The patient interface of claim9, wherein the flexible cushion is configured to be simultaneouslycoupled to the removable pressure port and the air delivery tube atdifferent locations on the flexible cushion.
 23. The patient interfaceof claim 22, wherein the different locations on the flexible cushion areon opposite lateral sides of the flexible cushion.
 24. The patientinterface of claim 9, wherein the upper and lower bridges are positionedso that there is a gap between the upper and lower bridges and betweenthe lateral portions of the frame, wherein the flexible cushioncomprises a central thickened portion at which an elastomeric wallthickness of the flexible cushion is greatest, and wherein the centralthickened portion of the flexible cushion is received by and extendsthrough the gap.
 25. The patient interface of claim 24, wherein a rim ofthe gap in the frame has the same shape as the perimeter of the centralthickened portion of the flexible cushion.
 26. The patient interface ofclaim 24, wherein the central thickened portion of the flexible cushioncomprises an array of vent openings.
 27. The patient interface of claim9, wherein a width of the upper bridge is greater than a width of thelower bridge.